In electronic circuit systems, unwanted signals can lower the dynamic range of a system or damage it if the power level is high enough. Bandstop filters can be used (e.g., in radio frequency (RF) and microwave systems) to reject unwanted signals from entering a receiver or leaving a transmitter. For example, bandstop filters can be used in RF and microwave systems to remove unwanted signals over a specific frequency range while passing signals with frequencies that fall outside of that range. These unwanted signals can originate from co-site or externally generated interference as well as nonlinear components under high-power excitation in the system.
Bandstop filters used in RF/microwave systems can be made tunable to excise unwanted signals at specific frequencies. Precise center-frequency tuning requires significant digital processing and adds delay. Conventional devices have high response time, complexity, size, weight, computation power, and cost. Further, conventional devices require a system to analyze a spectrum, compute an ideal filter frequency, and tune a filter with dedicated control signals. Additionally, conventional devices require temperature and vibration compensation, which adds significant overhead to the receiver.
Features and advantages of the present disclosure will become more apparent from the detailed description set forth below when taken in conjunction with the drawings, in which like reference characters identify corresponding elements throughout. In the drawings, like reference numbers generally indicate identical, functionally similar, and/or structurally similar elements. The drawing in which an element first appears is indicated by the leftmost digit(s) in the corresponding reference number.